Electrical components with chamfered mounting rings

ABSTRACT

Electrical components, such as insulated terminals, transistor sockets and the like, having a distortable dielectric body adapted to be press-fitted in an unchamfered opening in a chassis or other support, the distortable body having a diameter greater than the opening into which it is to be inserted and provided with a chamfered mounting ring of a size to seat against the chassis in an area surrounding the opening, the chamfered mounting ring acting to define a chamfer for the opening so that the distortable body may be readily inserted therein.

United States Patent Inventor Hilliard Dozier Cincinnati, Ohio App]. No. 21,797 Filed Mar. 23, 1970 Patented Aug. 24, 1971 Assignee U.S. Terminab, Inc.

Cincinnati, Ohio ELECTRICAL COMPONENTS WITH CI-IAMFEREI) I MOUNTING RINGS 7 Claims, 6 Drawing Figs.

[1.8. CI ..339/126RS, 16/2, 174/153 R, 248/56 Int. Cl. 1102b 1/02 FieldolScarch 339/59-61;

[56] References Cited UNITED STATES PATENTS 3,142.526 7/1964 Edwards 339/126 RS 3,244,801 4/1966 Dozier 339/126 J Primary Examiner-Joseph H. McGlynn Attorney-Melville, Strasser, Foster & Hoffman l I Z ELECTRICAL COMPONENTS WITH CI-IAMFERED MOUNTING RINGS BACKGROUND OF THE INVENTION In conventional press-fitted terminals, the terminal pin or electrode is mounted in an insulator composed of a distortable dielectric material, such as Teflon. The insulator normally has a cylindrical body which is beveled at one end and has an enlargecl head at its opposite end, the cylindrical body being adapted to be press-fitted into an opening in a terminal board or the like which is somewhat smaller in diameter than the cylindrical body of the insulator. In order to facilitate the insertion of the larger diameter insulator into the opening, the periphery of the opening has heretofore been chamfered to receive the body of the insulator, which is forced through the opening until the enlarged head seats against the terminal board. The terminal is thus held in place by the gripping engagement of the wall surface of the opening encircling the larger diameter insulator, which is constricted or pinched inwardly by the opening. In addition, the portion of the insulator body which lies on the opposite side of the opening expands radially outwardly to reassume its initial diameter, and hence further acts to maintain the insulator body in tight engagement with the chassis. Similar considerations apply to a transistor socket in that the body of the socket is forced into an undersize chamfered opening which distorts and constricts the socket in the area of the opening.

A major objection to the press-titted type of component lies in the fact that the chassis openings must be chamfered, usually on both sides, since in many installations the components are selectively inserted from one side or the other of the chassis. Such chamfering operations add to the cost of the chassis, particularly when it is considered that many chassis have multiple purpose uses and for a given installation only a portion of the openings may be utilized. This results in chamfering operations which may not be needed, depending upon the particular circuitry being assembled.

In contrast to the foregoing, the instant invention provides what literally amounts to a portable chamfer, the distortable dielectric body having a mounting member in the form of a chamfered ring adapted to seat over an opening in the chassis, the chamferedmounting ring serving to constrict the body so that it may be readily pressed into the opening.

RESUME OF THE INVENTION In accordance with the invention, essentially press-fitted components may be readily inserted as required in unchamfered openings, and the components may be mounted from either side of the chassis in either circular openings or in openings of other configurations, such as the so-called D openings. Simple pressure on the component forces its distortable body through the chamfered mounting member and the underlying unchamfered opening in the chassis, where it expands to lock the component in place. The components may be installed by automatic equipment, or with simple manual pressure.

The chamfered mounting members may be separately provided for association with the distortable bodies at the time of installation, or the mounting members may be preassembled with the distortable bodies to form integral units which may be handled and installed as a one-piece assembly.

Depending upon the conditions of use, the chamfered mounting member may be formed from metal or from an essentially rigid plastic material, such as an acrylic resin, which will resist dilation by the distortable body as the body is pressed through the mounting ring.

DESCRIPTION or THE DRAWINGS FIG. 1 is an exploded vertical sectional view illustrating a chassis, an electrical terminal, and a chamfered mounting member prior to assembly.

FIG. 2 isa vertical sectional view similar to FIG. 1 illustrating the parts in the assembled condition.

FIG. 3 is an exploded vertical cross section of a transistor socket and chamfered mounting ring prior to their preassembly;

FIG. 4 is a vertical sectional view showing the preassembled transistor socket and chamfered mounting ring in association with a chassis prior to final assembly.

FIG. 5 is a vertical sectional view illustrating the transistor socket and mounting ring of FIG. 4 in fully assembled condition in chassis.

FIG. 6 is a plan view of the fully assembled terminal illustrated in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1 of the drawings, there is illustrated a conventional press-fit terminal of the standoff type, the terminal having an electrode or conductor pin 1 and an insulator 2. The electrode includes a cap 3 which seats against the enlarged head 4 of the insulator which overlies the insulator body 5. It will be understood that the electrode is inserted in an axial bore in the insulator which opens inwardly from the enlarged head, the electrode being fixedly secured in the axial bore by means of barbs or the like, which are not shown but will be well understood by the worker in the art. The insulator is normally formed from a distortable dielectric material, such as Teflon; and it is customary to bevel the free end of the insulator body, as indicated at 6. Terminals of this type have been manufactured for a number of years and their electrodes may take various forms and shapes, none of which constitute a limitation on the present invention.

In accordance with the invention, the insulator body 5 is inserted in the unchamfered opening 7 inchassis 8 utilizing the mounting member 9 which has a chamfered opening 10 therein adapted to overlie the opening 7 in the chassis. Normally the body 5 of the insulator will be of cylindrical configuration, as will be the opening 7 in the chassis and the chamfered opening 10 in the mounting member. The diameter of the body member 5 will be larger than the diameter of the opening 7, usually by about 0.012 inch. For practical purposes, it is extremely difficult if not impossible to insert the body of the terminal directly into the unchamfered opening 7 without scoring or otherwise damaging the insulator. The mounting member 9 acts to provide a chamfered surface which serves to lead the insulator body into the opening 7. To this end, the inside or smallest diameter of the chamfered opening l0'will be substantially no greater than the diameter of the opening 7, and will taper outwardly so that its largest diameter will be substantially equal to or even slightly larger than the diameter of the insulator body 5. By way of example, if the opening 7 in the chassis has a diameter of 0. l 72 inch, the insulator body 5 will have a diameter of about 0. l 84 inch, and the mounting member 9 preferably will have an inside diameter of 0.172 inch or less and an outside diameter of about 0.l inch. The mounting ring thus serves to constrict the insulator' body 5 for entry into the opening 7 in the chassis, whereupon as the parts assume the fully assembled position illustrated in FIG; 2, the undersurface of the enlarged head 4 of the insulator will seat against the mounting member 9, with the distal end of the body 5 projecting outwardly through opening 7 on the opposite side of the chassis. As the distal end of the body passes beyond the opening in the chassis, it will tend to expand outwardly to its original diameter, thereby providing an expansion shoulder 11 which assists in securing the terminal to the chassis.

For practical purposes, it is preferred that the inside diameter of the chamfered opening in the mounting ring be slightly smaller than the diameter of the opening 7 in the chassis (about 0.004 inch) so as to constrict the body for ready passage through the opening 7. However, it is to be understood that the principles of the invention are equally applicable where the inside diameter of the chamfered opening in the mounting ring is equal to or even a few thousandths inch larger than the diameter of the unchamfered opening 7 in the chassis. Normal manufacturing tolerances will in themselves result in variations of several thousandths of an inch or more in the dimensions of the parts.

The mounting member 9 may be formed from metal or, for that matter, from any other suitable material, including plastics, which are sufficiently rigid and nondistortable to resist radial expansion by the insulator body. The cross-sectional dimensions of the mounting member do not constitute limitations on the invention, although by way of example, it may have a thickness of about 0.032 inch. Obviously, the mounting member should be sufficiently thin to permit the distal portion of the insulator body 5 to pass completely through the opening 7 in the chassis so that its projecting end portion may expand outwardly to assist in securing the insulator in place. This, of course, is a combined function of chassis thickness and mounting member thickness in relation to the overall length of the insulator body 5. The outside diameter of the mounting member is not critical, the only real consideration being to make the wall surfaces of the mounting member of sufficient size and strength to withstand rupture or radial expansion during the insertion of the insulator.

The mounting members 9 may be provided as separate pieces and associated with the terminals at the time of their insertion into the openings in the chassis. Alternatively, the parts can be preassembled, the mounting member being fitted over the distal end of the insulator body 5. Since the smallest diameter of the chamfered opening in the mounting member is substantially smaller than the diameter of the insulator body 5, the mounting member will remain in tight engagement with the insulator body. However, where it is desired to preassemble the insulator body and the mounting member, it is preferred that the body be provided with a second, somewhat smaller diameter portion at its distal end to receive and retain the mounting member. This avoids the possibility of the mounting member being inserted too far along the body so that the distal end of the body is free to expand radially outwardly on the opposite side of the mounting member, which would prevent it from being inserted in the unchamfered opening in the chassis.

Referring now to FIGS. 3 through 6 of the drawings, a construction is shown wherein the dielectric body has a smaller diameter portion at its distal end for preassembling the mounting member. The embodiment also illustrates the application of the invention to a transistor socket, although it is to be understood that the configuration of the distortable body is equally applicable to terminals and other similar components. The socket 12 has a slightly enlarged head 13, a main body portion 14 and a secondary, smaller diameter body portion 15. A plurality of conductor pins 16 project from the socket, the pins extending upwardly within the socket where they define pin-receiving receptacles into which additional conductor pins are adapted to be inserted through openings 17 in the upper surface of the enlarged head 13, such openings being seen in FIG. 6. The socket illustrated is of the so-called D" shaped configuration, having a flat surface 18 extending the full length of the socket. This is merely exemplary of the fact that the distortable body may be of other than round configuration.

The mounting member is shown at 9a, the member having a chamfered opening a; and in this instance the chamfer is shown to be formed on a radius rather than as a straight line taper, as illustrated in the embodiment of FIGS. 1 and 2. Either form of chamfer may be employed. The transistor socket is adapted to be inserted in an unchamfered opening 7a in the terminal board or chassis 8a; and in the embodiment illustrated both the unchamfered opening 7a and the chamfered opening 10a in the mounting member will have a flat or straight edge corresponding to the flat surface 18 of the socket body, such edge being indicated by the dotted line 19 in FIG. 6, the dotted portion 20 indicating the remainder of the periphery of the opening 7a in the chassis and also the periphery of the secondary body portion of the socket.

' In an exemplary embodiment of the invention wherein the main body portion 14 has a diameter of 0.374 inch and the secondary body portion 15 has a diameter of 0.362 inch, the chamfered opening 10a in the mounting member will have an inside diameter of 0.359 inch and an outside diameter of 0.385 inch. Thus, the inside diameter of the chamfered opening in the mounting member is on the'order of 0.003 inch smaller than the diameter of the secondary body portion 15. It is also preferred that the length of the secondary body portion 15 be slightly greater than the thickness of the mounting member 9a' so that the lower surface of the secondary body portion will project beyond the mounting member andhence may be utilized as a pilot to align and guide the socket into the opening in the chassis. A socket of the. dimensions just described is adapted to be inserted into an unchamfered opening 7a having a diameter of 0.359 inch, although as previously discussed, this dimension may be varied by a few thousandths inch, the chassis opening preferably being several thousandths inch larger than the inside diameter of the chamfered opening in the mounting member. It will be understood that the same relative dimensions will be applicable to the flat surfaces 18 of the socket and the straight edge 19 of the openings. Thus, the parts when preassembled will assume the condition illustrated in FIG. 4 wherein it will be seen that the lower surface of the secondary body portion 15 projects slightly beyond the under surface of the mounting member 9a and hence the exposed surfaces of the secondary body will serve as a guide or pilot to position and align the socket relative to the opening in the chassis. Upon final assembly to the chassis, the parts will assume the position illustrated in FIG. 5, wherein it willbe seen that the main body portion 14 is of a length such that it will extend completely through the opening 7a in the chassis and will be tightly gripped thereby, with its projecting portion defining an expansion shoulder 11a.

As should now be evident, the instant invention effectively eliminates the necessity for chamfering the openings in a terminal board or chassis to receive press-fitted parts, such function being performed by a portable chamfer in the form of a mounting member which may be associated with the part at the time of its assembly tothe chassis or preassembled with the part so that the part and its mounting member comprise a one-piece assembly. Modifications may be made in the invention without departing from its spirit and purpose. Numerous such modifications have already been indicated and others will undoubtedly occur to the worker in the art. For example, while the invention has been described asit applies to insulated terminals and transistor sockets, it should be evident that it can be equally applied to other installations wherein it is desired to fixedly mount a part in an unchamfered opening. While it is desirable for the distortable body to have an enlarged head on one side to serve as a seat for determining correct installation depth of the part, such enlarged head may be omitted if desired, the proper depth or position of insertion being determined by other means, such as a jig or the like which will establish the assembled position of the part. The mounting member also readily lend themselves to automation in that they may be formed as continuous belts or ribbons from which the individual members may be separated at the time of installation or as an incident of a preassembly step.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination with an electrical component or the like having a distortable body which is to be inserted in an unchamfered opening in a support, such as a chassis, the distortable body having a larger diameter than the opening in the support, an essentially nondistortable mounting member adapted to seat againstsaid support and having a chamfered opening therein adapted to overlie the opening in the support, said chamfered opening havingan inner diameter on the side of the mounting member facing the support which is substantially no larger than the diameter of the opening in the support and an outer diameter on its opposite side which is substantially equal to, but preferably slightly larger than, the diameter of the distortable body, whereby the chamfered opening in defines a guide by means of which said distortable body may be positioned and aligned relative to the opening in said support.

4. The structure claimed in claim 3 wherein saiddistortable body has a main body portion and a secondary body portion at its distal end, said secondary body portion being of smaller diameter than said main body portion but of slightly larger diameter than the inner diameter of the opening in said mounting member, said mounting member surrounding and engaging said secondary body portion when in its preassembled condition. a v

5. The structure claimed in claim 1 wherein said distortable body includes an enlarged head spaced from one end of said body, said head being adapted to seat against said mounting member when the said end of the distortable body is inserted in the opening of the support.

6. The structure claimed in claim 5 wherein said distortable body is formed from a dielectric material, such as Teflon, and comprises the insulator of an electrical terminal.

7. The structure claimed in claim 6 wherein said distortable body is formed from a dielectric material, such as Teflon, and comprises a transistor socket. 

1. In combination with an electrical component or the like having a distortable body which is to be inserted in an unchamfered opening in a support, such as a chassis, the distortable body having a larger diameter than the opening in the support, an essentially nondistortable mounting member adapted to seat against said support and having a chamfered opening therein adapted to overlie the opening in the support, said chamfered opening having an inner diameter on the side of the mounting member facing the support which is substantially no larger than the diameter of the opening in the support and an outer diameter on its opposite side which is substantially equal to, but preferably slightly larger than, the diameter of the distortable body, whereby the chamfered opening in said mounting member will act to radially compress the distortable body for entry into the opening in the support as the body is pressed through the chamfered opening in the mounting member from the outer diameter side thereof.
 2. The structure claimed in claim 1 wherein said mounting member comprises a ring which is preassembled to the distal end of said distortable body.
 3. The structure claimed in claim 2 wherein the distal end of said distortable body projects slightly beyond said ring and defines a guide by means of which said distortable body may be positioned and aligned relative to the opening in said support.
 4. The structure claimed in claim 3 wherein said distortable body has a main body portion and a secondary body portion at its distal end, said secondary body portion being of smaller diameter than said main body portion but of slightly larger diameter than the inner diameter of the opening in said mounting member, said mounting member surrounding and engaging said secondary body portion when in its preassembled condition.
 5. The structure claimed in claim 1 wherein said distortable body includes an enlarged head spaced from one end of said body, said head being adapted to seat against said mounting member when the said end of the distortable body is inserted in the opening of the support.
 6. The structure claimed in claim 5 wherein said distortable body is formed from a dielectric material, such as Teflon, and comprises the insulator of an electrical terminal.
 7. The structure claimed in claim 6 wherein said distortable body is formed from a dielectric material, such as Teflon, and comprises a transistor socket. 